225 research outputs found

    Endogenous bone marrow stem cell mobilization in rats: Its potential role in homing and repair of damaged inner ear

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    AbstractThe stem cells are widely used in the last few years in different fields of medicine, either by external transplantation or endogenous mobilization, most of these studies are still experimental on animals; few were tried on humans as in the spinal cord injury or myocardial infarction. As regards its use in the inner ear, stem cell transplantation was examined in many previous studies, while the mobilization idea is a new method to be experimented in inner ear hair cell regeneration.The aim of this work was to assess the use of GCSF to induce bone marrow SC mobilization to home and repair the damaged inner ear hair cells in rats after the damage had been inflicted by Amikacin injection.First we had to develop an animal model for damaged inner ear, so we used the well known ototoxic effect of Amikacin intra-tympanic injection till we reached complete loss of hearing function. And this can be assessed by DPOAEs. Now we have an animal model of damaged inner ear hair cells and mobilization of bone marrow SCs was induced by subcutaneous injection of G-CSF for 5days.Clinical assessment was done using DPOAEs before and after G-CSF injection also histological assessment of the inner ear was done before and after G-CSF by two methods H&E staining and Scanning Electron Microscopy.The results of histological examination of the specimens showed some promising changes that may be responsible for the improvement of hearing function in some rats that was detected by OAEs

    Shunt Hybrid Active Power Filter Based on Two Compensation Strategies with PI and Fuzzy Logic Controllers

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    Industrial designs have tremendously changed within the last decade, with its time and nonlinear variation loads in power frameworks spectrum expanding widely. This revolution has resulted in increased quality control problems such as current unbalance, current and voltage harmonics, flicker and poor power factor in control frameworks. The aim of this paper is to address this problem through the development of Synchronous Reference Frame and Reactive Power (SRF and P-Q) control methods. The DC voltage was regulated to its set reference for providing the current reference using proportional-Integral (PI) and fuzzy logic controllers. From the results, Fuzzy logic control was shown to achieve an adequate DC capacitor energy storage optimization, the sinusoidal type of the current and the change of the power factor. A low Total Harmonic Distortion (THD) that met the suggestions of IEEE- 519 standard on symphonious levels was achieved with the proposed method

    Copper(II)-oxaloyldihydrazone complexes: Physico-chemical studies: Energy band gap and inhibition evaluation of free oxaloyldihydrazones toward the corrosion of copper metal in acidic medium

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    AbstractA series of oxaloyldihydrazone ligands were prepared essentially by the conventional condensation reaction between oxaloyldihydrazide and different aldehydes e.g., salicylaldehyde, 2-hydroxy-1-naphthaldehyde, 2-hydroxyacetophenone and 2-methoxybenzaldehyde in 1:2M ratio. The synthesized compounds were purified to give bis(salicylaldehyde)oxaloyldihydrazone (L1), bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone (L2), bis(2-hydroxyacetophenone)oxaloyldihydrazone (L3) and bis(2-methoxybenzaldehyde)oxaloyldihydrazone (L4). All the oxaloyldihydrazones (L1–L4) and their relevant solid copper(II) complexes have been isolated and characterized by various physicochemical techniques. The identity of the synthesized compounds has been ascertained on the basis of elemental analyses, spectral (UV–Vis, IR, ESR, mass, 1H NMR), magnetism and thermal (TG) measurements. The dihydrazones coordinate to the metal center forming binuclear complexes. Upon chelation, the metal center can form a trigonal distorted octahedral structure with L1 and pseudo tetrahedral configuration with L2 & L3 & L4. The optical band gap energy for all compounds underlies the range of semiconductor materials. The investigated ligands were assayed for their corrosion inhibitive and adsorptive properties on copper surface in 1M HCl solution using weight loss technique. The results pointed out that, the ligands have a plausible inhibition toward the corrosion of copper specimen. The adsorption reaction on copper surface was found to be spontaneous first order and agreed with physical adsorption mechanism. The adsorption data fitted well to Freundlich, Langmuir and Frumkin adsorption isotherms

    Design and analysis of 1-to-4 Wilkinson power divider for antenna array feeding network

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    In this paper, A Novel 1 to 4 modified Wilkinson power divider operating over the frequency range of (3 GHz to 8 GHz) is proposed. The design perception of the proposed divider based on two different stages and printed on FR4 (Epoxy laminate material) with the thickness of 1.57mm and ϵr =4.3 respectively. The modified design of this power divider including curved corners instead of the sharp edges and some modification in the length of matching stubs. In addition, this paper contain the power divider with equal power split at all ports, reasonable insertion loss, acceptable return loss below -10 dB, good impedance matching at all ports and satisfactory isolation performance has been obtained over the mentioned frequency range. The design concept and optimization development is practicable through CST simulation software

    Design, synthesis and cytotoxic evaluation of 2-amino-4- aryl-6-substituted pyridine-3,5-dicarbonitrile derivatives

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    Purpose: To synthesize novel pyridine derivatives and evaluate their efficiency as potent inhibitors of cyclin dependent kinase 2 (CDK2) enzyme for cancer therapy.Methods: Pyridine scaffold were synthesized using one-pot multicomponent condensation reaction of arylidine with different primary amines. The cytotoxic potential of the new compounds was assessed using various cell lines. Furthermore, molecular docking studies based on the crystal structure of CDK2 was carried out to determine the possible binding modes that influence the anticancer activities.Results: The results indicate that one-pot multicomponent reaction generated a series of functionalized pyridines with good yield. In vitro cytotoxicity study revealed superior cytotoxicity of the designed compounds against prostate and cervical cancer cell lines compared to 5-fluorouracil (standard anticancer compound) with half-maximal inhibitory concentration (IC50) values of 0.1 – 0.85 and 1.2 –74.1 μM, respectively. Finally, molecular modeling simulation of the newly synthesized compounds showed that they fit well and are stabilized into CDK2 active site via hydrogen bonding and hydrophobic interactions.Conclusion: The results indicate that the newly synthesized pyridine can exert potent anticancer activity presumably via inhibition of CDK2. However, this will need to be confirmed in in vivo studies

    Chicory abrogates oxidative stress, inflammation and caspase-dependent apoptosis in acute hepatic injury model induced by acetaminophen in rats

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    In this study the protective effect of chicory leaves hydroalcoholic extract (CIE) against acute liver injury induced by a single dose of acetaminophen (700 mg/kg, i.p.) was investigated in rats. The CIE and silymarin treatment (standard reference) were given in a dose of (100 mg/kg, p.o.) for 3 days before and at 1 and 12 h following acetaminophen administration. Treatment with CIE significantly reduced the levels of serum ALT, AST, alkaline phosphatase, bilirubin, total cholesterol, triglycerides, urea, creatinine, TNF-α and hepatic contents of malondialdehyde (MDA), nitric oxide, caspase-3 and hydroxyproline, with significant increases in serum total protein, albumin, HDL- cholesterol and hepatic activities of reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) as compared with the acetaminophen group. The histopathological alterations mediated by acetaminophen were ameliorated by CIE. It was concluded that CIE protects rat liver against acetaminophen hepatotoxicity, most probably through abrogation of oxidative stress, inflammation and caspase-3 dependent apoptosis

    Physical activity in pregnancy prevents gestational diabetes: A meta-analysis

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    AimsThe effectiveness of physical activity (PA) programs for prevention of gestational diabetes (GDM) lacks conclusive evidence. The aim of this study was to generate clear evidence regarding the effectiveness of physical activity programs in GDM prevention to guide clinical practice. MethodsPubMed/Medline, ISI Web of Science, Scopus, and EMBASE were searched to identify the randomized trials (RCTs) published until June 2019. Randomised controlled trials enrolling women at high risk before the 20th week of gestation comparing the effect of PA interventions with usual care for prevention of GDM were retrieved. Data obtained were synthesised using a bias-adjusted model of meta-analysis. ResultsA total of 1467 adult women in 11 eligible trials were included. The risk of GDM was significantly lower with PA, but only when it was delivered in the healthcare facility (RR 0.53; 95% CI 0.38–0.74). The number needed to treat with PA in pregnancy (compared to usual care) to prevent one GDM event was 18 (95% CI 14 – 29). The overall effect of PA interventions regardless of location of the intervention was RR 0.69 (95% CI 0.51 – 0.94). ConclusionsThis study provides evidence that in-facility physical activity programs started before the 20th week of gestation can significantly decrease the incidence of GDM among women at high risk

    Longitudinal changes in peri-papillary retinal nerve fiber layer thickness in patients with unilateral branch retinal vein occlusion

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    Background: Associations between retinal venous occlusion (RVO), elevated intraocular pressure, and glaucoma have been reported. Further investigations into structural alterations in the fellow eyes of individuals with unilateral RVO have revealed that the peripapillary retinal nerve fiber layer is thinner than in healthy eyes, suggesting that there may be systemic risk factors common to both RVO and glaucoma. We aimed to evaluate changes in peripapillary retinal nerve fiber layer thickness (pRNFLT) among individuals with unilateral branch retinal vein occlusion (BRVO). Methods: This prospective observational study recruited 30 individuals (60 eyes) with newly diagnosed unilateral BRVO and macular edema, and a control group of 30 healthy individuals (30 eyes) with no abnormalities on fundus examination or concurrent systemic comorbidities. After baseline measurements, the participants were reassessed at 6, 12, and 24 months by measuring global and sectoral pRNFLT using spectral-domain optical coherence tomography. Results: The mean age and sex distributions were comparable between the patient and control groups (both P > 0.05). When compared to fellow eyes, global and sectoral pRNFLT in eyes with BRVO were significantly higher at baseline (all P < 0.05). Over time, pRNFLT decreased dramatically, and by the conclusion of the two-year follow-up, there was a significant reduction from baseline in the affected eyes (all P < 0.05). Likewise, affected eyes experienced a significant improvement in best-corrected distance visual acuity and central macular thickness over the two-year follow-up (both P Less than or equal to 0.001). Comparing the global and all-sector pRNFLT of fellow eyes in the patient group with those of normal eyes in the control group, there were no significant differences at any visit, except in the temporal sector, which revealed a significant reduction in pRNFLT at 24 months in the fellow eyes of patients with unilateral BRVO (P = 0.02).   Conclusions: Patients with unilateral BRVO experienced a significant reduction in pRNFLT in the affected eyes and, to a lesser extent, in the fellow eyes, compared with that of the control arm, suggesting that they are prone to retinal nerve fiber layer damage. The reduction in pRNFLT in the normal fellow eyes of patients with BRVO may be attributed to age or concurrent systemic comorbidities. Further studies with long follow-up periods are required to shed light on the etiology of functional and structural changes in both the retinal nerve fiber layer and ganglion cell complex in the normal and affected eyes of patients with unilateral BRVO
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